This disclosure relates to test and measurement instruments and, in particular, to test and measurement instruments having marks.
As the technology for test and measurement instruments advances, longer record lengths have become available for storing digitized signals. Because of such long record lengths, it is impractical for a user to manually examine the digitized signal for interesting events. A user may zoom in on a digitized signal to see interesting events in sufficient detail; however, because of the long record length, it would take the user an unacceptable amount of time to pan the display to search through the digitized signal. The user may zoom out so that panning though the digitized signal may be performed in an acceptable amount of time. However, the level of detail is reduced such that the user may not see interesting events. In addition, positions of the zoom window may be manually entered; however, a user is required to manually record a position of an interesting event and manually enter the position to return to that position.
A conventional logic analyzer (a type of test and measurement instrument) may include a search function that moves a zoom window to display the next event on a digitized signal. However, the current and previous events are not recorded. As a result, the user is prevented from navigating among or recording the positions of the interesting events. Furthermore, the user cannot manually define interesting events.
Cursors have been implemented in test and measurement instruments. However, cursors only indicate a point on a displayed digitized signal. In addition, a cursor cannot be used to navigate around a digitized signal.
Accordingly, there remains a need for an improved method and apparatus for examining digitized signals.